Construction of LDH-Derived Bimetallic Metal–Organic Framework with Defect Engineering for High-Performance Supercapattery Application

This research focuses on the defect-driven surface modification of a bimetallic NiMn-based metal–organic framework (LDH-D NiMn-MOF) achieved through the in situ transformation of a layered double hydroxide (LDH). The defect-engineered LDH-D NiMn-MOF demonstrated enhanced performance as a supercapattery material compared to Direct NiMn-MOF and NiMn-LDH. This enhancement is attributed to its hierarchical structure, better redox properties, the synergistic effects of the two metal ions, extrinsic hydrophilicity, and the alteration of its electronic structure, which results in a greater number of reactive sites. LDH-D NiMn-MOF displayed a storage capacity of 489 C g⁻¹, exceeding that of NiMn-LDH (423 C g⁻¹) and Direct NiMn-MOF (258 C g⁻¹) at a current density of 3 A g⁻¹. Furthermore, an aqueous asymmetric supercapattery device is constructed using LDH-D NiMn-MOF and Fe_xO_y- CNF-PO-300 as cathodic and anodic material, achieving a maximum energy density of 55.99 Wh kg⁻¹ and a power density of 6.83 KW kg⁻¹, with 94.4% specific capacity retention after 6000 charge–discharge cycles at 10 mA cm⁻². Hence, this study offers an effective synthesis strategy for developing a defect-engineered bimetallic MOF utilizing layered double hydroxide as a scaffold, showcasing its potential as an efficient electrode material for energy storage.